Presentation by James T. CurrieLegislative Director
National Marine Manufacturers AssociationFebruary 5, 2013
I am here today to speak with you on behalf of the National Marine Manufacturers Association,
which represents over 1500 boat builders and marine engine and marine accessory manufacturers. But
what I am going to tell you about marine engines and e15 ethanol is also applicable to other engines
such as those in snowmobiles, motorcycles, ATVs, and lawn and garden equipment because the
combustion chemistry of these engines is basically the same.
I should say in the beginning that outboard engines are as tough as they come. Think about how
you run a boat engine: you bring the boat up on plane and you shove the throttle all the way forward
and go as fast as you can. That’s what people routinely do with boat engines, so they are designed and
built to tough specifications. Yet even the best of them are no match for e15 ethanol.
The tests I am going to describe this morning, the results I am going to show you in pictures,
were conducted at the Mercury Marine test facility in Fond du Lac, WI, in 2010-2011 by Mercury
personnel under contract to the US Department of Energy and coordinated by the National Renewable
Energy Lab (NREL). The final report was released by the Department of Energy in October 2011, and it
can be found on the NREL web site. That’s where the photos come from.
The objective of these tests was to understand the effects of running a 15% ethanol blend on
outboard marine engines during 300 hours of wide open throttle (WOT) endurance testing—a typical
marine engine durability test. Three separate engine families were evaluated. A 9.9 HP carbureted four-
stroke engine and a 300 HP supercharged electronic fuel injected (EFI) four-stroke engine represented
current products. A 200 HP electronic fuel injected (EFI) two-stroke engine was chosen to represent the
legacy products still in widespread use today. Two engines of each family were evaluated. One test
engine was endurance tested on e15 fuel, while a second control engine was endurance tested on
ethanol-free gasoline.
The primary point to remember when considering this test is that ethanol, in any blend, is an
oxygenator. E10 fuel has 3% oxygen while e15 fuel has 5%-6% oxygen. On any engine this additional
oxygen makes the fuel burn hotter—just as blowing on your fireplace to get it started makes the fire
burn hotter—and the higher temperatures can reduce the strength of the metallic components in the
engines.
You can see from the photos just what happened to these engines. I have large photo blow-ups
here at the front of the room, and there are color photos in the copy of my testimony that is available
with the other hand-outs.
Mercury was able to complete the entire 300 hour test running e15 in the 9.9 HP engine, which
is a small outboard like you might find on a rowboat or a sailboat. Test results indicated poor running
quality, including misfires at the end of the test. The poor run quality caused an increase in exhaust
emissions. In addition, there were increased carbon deposits in the engine on the underside of the
pistons and on the ends of the rods indicating higher engine temperatures. You can see the difference in
the carbon deposits in this photo. Additionally, deterioration of the fuel pump gasket was evident. This
deterioration of the gasket could lead to fuel pump failure, disabling the engine.
The 300 HP four-stroke supercharged engine did not complete the endurance test on e15 fuel.
The engine encountered a valve failure after 285 hours of endurance testing. As you can see from the
photos, one valve broke apart, which ended the test, and two others developed cracks. I should mention
that these are high-quality valves constructed of Inconel, a high-temperature alloy that has been used in
rocket ship engines. Even so, when Mercury did metallurgical analysis on this engine, they found that
the cause of these fractures was deteriorated mechanical strength due to high temperature in the
combustion chamber. This is caused by the additional oxygen from the e15. The next photo shows a
comparison of the pistons and connecting rods from the Verado engine, also indicating that the e15 test
engine operated at elevated temperatures.
The 200 HP two-stroke engine using E15 fuel also failed to complete the endurance test. It
failed a rod bearing at 256 hours of testing, resulting in catastrophic destruction of the engine. You can
see the remains of the bearings in the photos. There was so much damage to the engine that we could
not determine the exact cause of failure. It is important to note that two-stroke engines of this type mix
the fuel and the oil and use that mixture to distribute the oil to the critical interfaces such as the
bearings and cylinder walls. Ethanol may have an effect on the dispersion or lubricity of the oil as it is
mixed with the fuel.
What I have presented to you in brief today—and what is available at the NREL website in full—
are the results of the limited testing conducted on three of Mercury’s outboard engine families. This
study showed how e15 would affect the millions of outboard engines currently in use and, by
extrapolation, engines of other types.
If we do this extrapolation to other types of engines, we can see the potential for extensive
costs to the American consumer, costs that could range into the billions of dollars. If you have a
lawnmower or a chain saw or a generator, the principles will be the same: high heat from the additional
oxygen that comes from an e15 blend, and that high heat will damage your engine. If you have a
motorcycle or a snowmobile, it’s the same thing. And if you have an older automobile or truck—
anything older than 2001 model year—the EPA says you should not run e15 in it.
I am not here to speak directly for the manufacturers of automobiles, but virtually every one of
them has said that their models through 2012 are not designed to run on e15, and if your engine is
damaged by doing so, your warranty is void. Back in December of last year the American Automobile
Association issued a press statement about e15 use. AAA said the following in that statement: “The only
vehicles currently approved by automakers to use E15 are flex-fuel models, 2001 model year and newer
Porsches, 2012 model-year and newer GM vehicles, and 2013 model year Ford vehicles.” That’s it. So
why are we continuing to allow the sale of a fuel that will ruin your boat engine, destroy your
lawnmower, harm your motorcycle, damage your snowmobile, and harm virtually every automobile and
light truck on the road. Well, that’s the question, Isn’t it? We will soon offer a plan for doing something
about this threat to our economy, so stay tuned.
Photos from Mercury Marine Outboard Tests